1. Field of the Invention
The invention relates to an oven, comprising a housing, heating means for heating the interior space of the housing, and a conveyor belt which extends between an inlet and an outlet of the housing, for passing products which are to be heated through the interior space, which conveyor belt has at least one helical path with turns which are situated above one another and are supported by means of guides, which extend in a corresponding way to the turns and are supported by bearing arms transversely below the turns, and collection means for the collection of liquids.
2. Description of Related Art
An oven is disclosed in EP-A 558 151. This oven is suitable for heating food products. Examples which are mentioned include meat products, such as chicken, hamburgers, schnitzels, cordon bleus and the like. The food products can be treated in various ways depending on the nature of the product. The temperature and residence time in the oven may, for example, be set in such a manner that a certain crust formation or browning is obtained. The conditions in the oven may also be selected in such a manner that a certain degree of cooking is achieved. In the known oven, these two treatments can be combined as a result of there being two zones, which may have different heating conditions.
The products may be heated in various ways. According to a first possibility, the oven is heated by means of hot-air heating. The hot-air heating may operate with heat-transfer oil or may be of the electrical type. According to another possibility, the oven is heated by means of steam.
When the products are being heated, processes occur which lead to moisture and other vapours being released. These circulate through the oven and may be deposited on the fixed surfaces thereof. In certain situations, such as when heating marinated meat, deposits may form which then burn as a result of the prolonged heating in the oven. These deposits may adopt the shape of icicles on all kinds of parts of the interior of the oven.
The icicle-shaped deposits may in particular occur on the bearing means for the guides over which the conveyor belt slides. It is also possible for the moisture and fat which drip off the conveyor belt to accumulate on this bearing means.
The icicle shapes formed in this way consist to a large extent of the burnt products of carbonized meat and fat and the like. The problem which arises in this context is that these burnt products may pass onto the products located on the conveyor belt. This can be caused by moisture dripping down along the icicle shapes and entraining the burnt products. The drops which fall off the icicle shapes as a result form discoloured spots on the products, which are unacceptable.
The prior art oven is provided with a strip which extends underneath a part of the conveyor belt, which strip is provided with collection means for collecting liquids which originate from windings of the conveyor belt which are the higher level. In the prior art oven, this strip separates two areas positioned on top of each other which can be brought in a different heating state. A disadvantage of this prior art embodiment is that a strip of this kind has large dimensions, and influences the air flow within the oven.
The object of the invention is to provide an oven of the type described above which does not have this drawback. This object is achieved by the fact that the collection means have an elongated shape and extend according to their longitudinal direction transverse with respect to the turns for the collection of liquids which may accumulate on the bearing arms and/or guides.
Any deposits which adhere to the bearing means, such as icicle shapes, can no longer give rise to the formation of spots on the products, since the drops which drop off them are intercepted in good time by the collection means.
These collection means may be designed in various ways. According to a first option, the collection means may be in gutter or receptacle form. The liquids collected can also be discharged via the gutter-like collection means to outside the area where the products are located on the belt.
The gutter or receptacle shape of the collection means can be implemented in various ways. According to a first embodiment, the bearing arms themselves are designed in such a way that they are in the shape of a gutter. The fat and the like which drips off the conveyor belts can be successfully collected by means of gutter-like bearing arms of this type.
According to a further embodiment, it is possible, if appropriate in addition to the variant described above, to provide separate gutter-like collection means which extend beneath in each case one bearing arm. In this way, the moisture which drips off the bearing arms themselves can also be collected.
The gutter-like collection means in this case comprise separate gutter profiled sections which extend beyond the outermost circumference of the turns. The gutters preferably run on a slope towards the outside of the turns and, in the vicinity of this outer side, are connected to a drainage pipe.
With a view to cleaning the oven, it is possible for an inlet nozzle for a cleaning liquid to be provided in the vicinity of the innermost circumference of the turns, for the purpose of rinsing the gutter-like collection means. The cleaning liquid can be discharged and collected via the discharge pipe.
According to a second possible option, a passage for supplying cleaning liquid to the inlet nozzle extends through the bearing means.
According to a further possible embodiment, the collection means are in plate form. In particular, the plate-like collection means may extend so as to follow the turns.